Ma. Samoilys, MOVEMENT IN A LARGE PREDATORY FISH - CORAL TROUT, PLECTROPOMUS-LEOPARDUS (PISCES, SERRANIDAE), ON HERON-REEF, AUSTRALIA, Coral reefs, 16(3), 1997, pp. 151-158
Movement by the larger more mobile species of coral reef fish plays a
significant role in determining patterns in abundance and population s
tructure. Fish movement is also relevant to the use and effectiveness
of marine reserves in managing fish populations. Coral trout are large
piscivorous serranids supporting major fisheries on the Great Barrier
Reef (GBR). This study reports on the within-reef movement of the com
mon coral trout, Plectropomus leopardus, at Heron Reef, southern GBR,
over a twelve month period, investigated by tagging and underwater tra
cking. Tracking of coral trout revealed no apparent relationship betwe
en the area moved and stage of tide or time of day. However, movement
areas were affected by the size of fish: in spring a linear relationsh
ip between fish size and area of movement was measured, but in summer
the largest (male) fish moved over significantly smaller areas than me
dium-sized fish. Movement of males may be related to cleaning behaviou
r and spawning. Fifty nine percent (n = 101) of the tagged fish were r
esighted over periods of 4-5 months, in ''home sites'' measuring simil
ar to 2000 m(2). Coral trout were not restricted to home sites, but mo
ved on average 2 km along the reef slope; maximum distances of 7-7.5 k
m were measured. Coral trout appear to range as mobile, opportunistic
predators, but also maintain home sites for access to shelter and clea
ning stations.